For architectural interior and exterior materials, building materials, furniture, and various components for home appliances etc., and in particular, kitchen products, bathroom shelves, and bathroom doors, base plates such as metal plates, inorganic plates (e.g., plaster board), and wood plates (e.g., MDF, particleboard, and laminated board), are used. On these plates are bonded together decorative sheets that are obtained by imparting aesthetic appearance to a plastic sheet used as a base material by applying a color, pattern, or unevenness. Due to a current increase in high-end consumers, specularity has also become an important performance required of these components, in addition to freshness and designability.
As a decorative sheet with specularity, a decorative sheet comprising a polyester film as a base material, a permeation-preventive layer, and a surface-protective layer in which an ionizing radiation-curable resin composition is cured by crosslinking has been proposed (e.g., Patent Literature (PTL) 1). However, when a decorative sheet in which a polyester film is used as a base material is used to wrap an adherend while heating (50 to 120° C.), the decorative sheet is softened and is likely to suffer from unevenness of a coating of a paste (adhesive) or surface irregularities of an adherend (i.e., “daku” in Japanese). This results in a decrease in specularity after being bonded to the adherend.